Protective vision device



y 1, 1945- D. J.'CRAWFORD ET'AL 2,374,665

PROTECTIVE VISION DEVICE Filed July 2, 1942 2 Sheets-Sheet 1 Inventors DavidLLErawfmr'r Joseph MJIulbv EJ Q/( K MMMM:

Atturneys Patented May 1, 1945 David J. Crawford, United States Army, Durant;

Miss., and Joseph M. Colby; United States Army,

Lake Mills, Iowa Application July 2, 1942, Serial No. 449,436

l (Granted under the act of Math, 3,1 1883', as 1 amended April 30, 1928; 370 G; 757) 1 Claim.

The invention described herein may be manufactured' and used by or for'the Government for governmental purposes, without the payment to us of any royalty thereon. 7

This invention pertains to protectoscopes, and more particularly tomeans'for protecting an observer stationed at an observation slit provided in an'armored device including means for replacing an optical systemtherein which has i been damaged. 1 i

An object of the invention'isto' provide an observation passage so formed-as to reverse 'and eliminate projectiles which enter the-observation passage.

Another object of theinvention is to provide an optical system of brittle material which will shatter into numerous small particles when struck by a projectile and thereby facilitateeasy removal from its mounting and permit aquick' replacement. i

Another object of the inventicnis to provide a protected, indirect observation sight for an armored device. v

A further object of the invention is to provide a simple, rugged mounting which will enable an observer to remove quickly and conveniently a damaged optical system from an observation position.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a, description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. 1 is a vertical section through a portion of the armored front of a device showing one embodiment of the optical system and its mounting.

Fig. 2 is a section on the line 2--2 of Fig. 1.

Fig. 3 is a rear view of the protectoscope in a tank door.

Fig. 4 is a sectional view showing the optical system support in the open position.

Fig. 5 is a vertical section of a rotary journal type protectoscope.

Fig. 6 is a sectional view on Fig. 5, and

Fig. 7 is a rear view of the rotary journal type protectoscope with a part broken away to show details of construction.

A vehicle or other device is equipped with protective armor plate I. An observation slit 2jis provided in the armor plate. The split 2 preferably diminishes in size near the rear or interior of the plate I and then developsinto an enlarged chamber 3 with an arcuate wall 4. The

the line 6-6 of wall 4 forms a cylindrically shaped bulge 5 with a hollow interior on the inner Wallof the device; The lower portion 6 of this metal bulge 5 (is pierced by a rectangular slot 1. A protectoscope 8 comprising a body portion}! and a frangible 45 mirror system It attachedthereto slides into meson.

The armor plate I, as shown in Figure 3, may

be the door of a combat vehicle, having hinge knuckles A and a suitable door operatingrnechanismBL' I I A support H is shaped to conform to the lower portion of the base of the protectoscope 8 and thereby hold it. The support II is' carried :b'yv

arms l2 which engage brackets 13 on-the bulge Ethrough pivot pins" i4. Paralleli'ng the rectangu'lar-slot 1 and at the rear of the support H is a longitudinal groove i5; A window l6 rests in this-groove and is of sufficient height to engage the lower rear wall H" of the bulge'5 when the support is in the closed positionas' shown inFig. 1.; This effectively seals the opening.

The-front end I 8 of the support l l engages the under portion of the lip H of the protective The lower edge of this front end l8 armor i. v carries agroove 20 having angular sides and extends the length of the support. The armor plate I carries spaced brackets 2| beneath the front end of the support II and these brackets have hinge portions 22 which receive their com- The upper plements 23 on a locking plate 24. end of plate 24 is adapted to engage the groove '20 in the support II and hold the support in its closed position. Leaf springs 25 are attached v at 26 to the ends of the plate 24 and are bent so that their free ends 2'! rest in pressure engagement with the rear wall 28. of the. armor plate. The springs 25 urge the plate 24into engagement with the groove 20 of the support II. and

hold it in its locked position to maintain the projectile. Frangible plastics such as, glass or I Lucite have proved eminently satisfactory. Frangible reflectors illmay be cemented to a periscope body 9 which is preferably constructed of a brittle transparent material. Frangible reflectors or a frangible optical system have a This protects his head from decided advantage over polished metal reflectors. Metal elements are fractured by a projectile and become bent or distorted. This genand a new one inserted whereupon the journal 30 is turned clockwise and the unit is again I ready for action. This type of a; protective vi erally impairs the immediate removal of the a damaged optical system since the recess 1 is smaller than the distorted and enlarged metal reflectors, Hence the employment of a frangible reflector or a frangible reflector and body increases the efficiency of an observation device from a military standpoint.

Another important feature of the invention is 1 the configuration of the observation slit 2 and its connecting cavity 3.' The smooth arcuatev ricochets in the cavity 3 andis ejected by its In its path the projectile shatters the brittle plasown momentum through the entering slit 2.

tie reflecting system and the momentum impar ed to these particles carries them against the deflecting wall 4 of the cavity 3 and eliminates them from the observation channel.

Pressure is applied to the plate 24 to over come the resistance of leaf springs 25. This rotates the plate counterclockwise about its hinge 23 and removes the upper end of the plate from the groove 20 in the support H. Support H is now free to rotate counterclockwise about the pivot pins l4 and drops open as shown in Fig. 4. The damaged optical system 8 falls out of its slot 1. Anew system may be inserted and the gate support I I swung into position and automatically latched by the spring pressed plate 24.

Fig. 5 delineates another embodiment in which the protectoscope 8 is mounted in a cylindrical rotor or journal 30. a suitable hollow bearing (not shown) in the protective armor. When the optical system 8 is destroyed by gunfire the journal is rotated counterclockwise until the hood or visor 3| seals the observation slit. The protectoscope 8 is removed The journal 30 rotates in sion device may be employed effectively near a gun port.

The construction of the protectoscope support H and its latching mechanism is similar to that shown in Fig. 1.

is altered slightly. A bracket 32 is fastened to the front wall 33 of the rotor 30 by screws 34'.

(See Figs. 5 and 6.) The bracket 32 is in the form of a bar which is somewhat shorter than the rotor and has a depending apron 35. The lower end of this apron is curved to form hinge members 36which engage a shaft 31. Similar members /on plate 24 complete the hinge and constitute the points about which the locking plate 24 oscillates. This bracket 32 eliminates the difficult machining and drilling of the thin fin 38 to receive a hinge and facilitates mass production. The springs 25 are attached to the plate 24- in the conventional manner and have their free ends 2! bearing on the bracket 32.

We claim:

A support fora periscope comprising a member having a substantially horizontal viewing aperture and a vertical aperture extending downwardly from said horizontal aperture adapted to receive a periscope, a hingedly connected sup port member having. a recess for,v mounting the lower end of a periscope therein and for sealing 3 member, and a manually releasable, spring urged locking member for locking said hingedly connected support member in sealing relationship with the bottom of said vertically extending aperture.

DAVID J. CRAWFORD.

JOSEPH M. COLBY.

For convenience in manufacturing the hinge arrangement for the plate 24 

